title: Phase I study of injectable, depot naltrexone for the relapse prevention treatment of opioid dependence.
abstract: OBJECTIVE
  We tested long-acting injectable depot naltrexone for its tolerability, pharmacokinetics, and safety in Phase I.
  
  
  METHODS
  The Phase I trial enrolled 36 healthy participants in two panels (A, B). In Panel A, 24 subjects were randomly assigned to the high-dosage group (400 mg naltrexone, n=6; placebo, n=6) or low-dosage group (200 mg naltrexone, n=6; placebo, n=6). In Panel B, 12 subjects were randomized to take six doses of monthly injectable naltrexone (400 mg) or placebo.
  
  
  RESULTS
  After a single injection of naltrexone 200 and 400 mg, means (SD) of naltrexone plasma concentrations were .57 (.28) ng/ml and 1.5 (.8) ng/ml 30 days post-injection. There was no effect of accumulation after multiple dosing. Eleven of 30 subjects (36.67%) who were administered injectable depot naltrexone reported a total of 12 adverse events (AEs). Seven of these 11 AEs were coded as possibly related with study medication. All treatment-related AEs were mild in severity. No serious treatment-related AEs occurred.
  
  
  CONCLUSIONS
  This long-acting formulation of injectable depot naltrexone is well tolerated, results in constant plasma concentration of naltrexone for at least 1 month.
  
  
  CONCLUSIONS
  The tolerability and safety of long-acting injectable depot naltrexone are good.
authors.affiliation: Mental Health Institute of the Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Xuyi
authors.forename: Wang
authors.initials: W
authors.lastname: Juelu
authors.forename: Xiang
authors.initials: X
authors.lastname: Xiaojun
authors.forename: Li
authors.initials: L
authors.lastname: Haiyan
authors.forename: Liu
authors.initials: L
authors.lastname: Zheyuan
authors.forename: Gong
authors.initials: G
authors.lastname: Zhehui
authors.forename: Dong
authors.initials: D
authors.lastname: Guoming
authors.forename: Liu
authors.initials: L
authors.lastname: Gang
authors.forename: Li
authors.initials: L
authors.lastname: Jin
authors.forename: Hao
authors.initials: H
authors.lastname: Wei
mesh_terms: D000328:Adult; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000009:adverse effects; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007267:Injections; D008297:Male; D009271:Naltrexone / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D009292:Narcotic Antagonists / Q000008:administration & dosage / Q000009:adverse effects / Q000097:blood; D009293:Opioid-Related Disorders / Q000517:prevention & control*; D055502:Secondary Prevention; D055815:Young Adult
chemical_list: D003692:Delayed-Action Preparations; D009292:Narcotic Antagonists; D009271:Naltrexone